Apparatus and methods for creating real-time 3-D images and constructing 3-D models of an object imaged in an optical system

ABSTRACT

Dynamic aperture microscopy in which the portion of an objective aperture that passes light in an optical system that images an object is continuously changed to create motion parallax which continuously changes the angle from which the object is viewed to create a moving 3-D view of the object from which a 3-D model of the object can be constructed that can be seen or measured from any angle.

FIELD OF THE INVENTION

The present invention relates to optical systems, and more particularly,to methods and apparatus for creating and capturing perceivable 3-Dimages of an object and constructing 3-D models of the object that canbe viewed and measured from any angle.

BACKGROUND OF THE RELATED ART

Based on the state of the art prior to the present invention, thecreation of a viewable 3-D image of an object in an optical system, suchas a microscope, requires the use of filters, dual imaging systems orexpensive viewing optics, all of which have their known disadvantages.The prior art has used the notion of convergence parallax orstereoscopic viewing from two angles simultaneously. In the presentinvention, we teach the use of motion parallax to create a perceivable3-D image.

Prior to the present invention, it has not been possible to view anobject in real-time 3-D through a standard microscope by the addition ofa relatively inexpensive add-on device or to create a tomographic modelof an object using such a device.

SUMMARY OF THE INVENTION

The present invention teaches methods and apparatus for obtaining 3-Dimages of an object in a standard microscope by continuously changingthe angle from which the image of the object is viewed. “View”,“viewing” and “viewed” as used throughout this specification refer todetection of an image by either the human eye or an optical orelectronic device or system.

A typical optical system for creating the image of an object, such as amicroscope, includes one or more aperture planes conjugate to theobjective lens aperture, such as the condenser lens aperture, the lightsource of the system, the eye-point of the eyepiece (or barlow lens) orany conjugate relayed aperture plane that uses relay lenses. When usedherein, “objective aperture” refers to the objective lens aperture andany aperture at a plane conjugate to the objective lens aperture.

The present invention teaches that by selecting an objective aperture ineither the illumination path or the viewing path of a light transmittingoptical system and continuously changing the portion of that objectiveaperture through which the light passes, motion parallax is created. Tothe viewer, the image of the object is continuously moving in a way thatmakes the foreground elements of the image distinguishable from thebackground elements. In this way, the image appears to the viewer in 3-Dwithout the need for any viewing aids, such as special 3-D spectacles orfilters. In fact, with the present invention, 3-D perception is evencreated in microscopes having only a monocular viewing head.

When the portion of the selected objective aperture that passes light iscontinuously changed, as, for example, by rotating an off-centeredopaque mask having an aperture (mask aperture) at an objective aperture,the image of the object will appear to move in an inclined rotarymotion, distinguishing the elements of the image in the foreground fromthose in the background.

If the portion of the selected objective aperture that passes light iscontinuously changed by a back and forth motion of a mask aperture inthe y-axis, then the image appears to rock back and forth. If the backand forth motion is in the x-axis, then the image will appear to rollfrom left to right.

The shape of the moving mask aperture will determine image properties,such as depth of field, definition (highlighting and shadowing effects),contrast, resolution and parallax angle differences. The presentinvention provides for control of image properties by selectingdifferent shapes and sizes for dynamic mask apertures. The dynamic maskapertures can be physical openings in otherwise opaque members or othermeans of occluding light, such as LCD shutter mechanisms, and can beinserted or removed from the light path as required.

In addition to a dynamic mask aperture for continuously changing theportion of a selected objective aperture that passes light, theadvantages of the present invention are also achieved by continuouslymoving a shaped light beam at a selected objective aperture so that theportion of the aperture which passes light is continuously changed. A“shaped beam” as used herein means a light beam that is shaped such thatit fills less than the entire objective aperture and as used hereinincludes, without limitation, masked beams, focused beams and an arrayof light-emitting diodes (LEDs). By locating an array of LEDs at anobjective aperture (such as a condenser lens aperture) and stimulatingdifferent ones of the LEDs in a timed sequence, it is possible, usingknown techniques, to continuously change the portion of the objectiveaperture that passes light. In such a case, the LED array is both theshaped beam and the light source.

Regardless of the particular motion generated or the particularstructures used to continuously change the portion of a selectedobjective aperture that passes light, the continuously moving imagecreated distinguishes the relative positions of the elements of theobject and the object can be detected in 3-D by continuouslyinterrogating the object from different points of view.

When the objective aperture is in the illumination part of the system,the benefits of oblique illumination are also imparted to the image.

Because the invention can be applied to an objective aperture in eitherthe illumination or viewing paths of an optical system, the presentinvention is useful in systems using transmitted illumination,reflection illumination or florescence.

The present invention permits the creation of a series of discrete,obliquely angled images at particular locations throughout the object.Such a series of images can be digitized and analyzed by a computerprogram that will create an accurate three-dimensional model of theobject that can be viewed and measured from any angle. Thus, theinvention, when combined with an optical viewing system, constitutes thehardware portion of a tomographic microscope.

It is an object of the present invention to create a 3-D image of anobject in an optical system without the use of viewing aides, such asspecial spectacles or the like.

It is an object of the present invention to create a viewable 3-D imageof an object in an optical system by creating motion parallax.

It is another object of the invention to create motion parallax in anoptical system for creating a 3-D image of an object by continuouslychanging the portion of an objective aperture through which lightpasses.

A further object of the present invention is to create a series ofimages of an object that can be digitized and analyzed by a computerprogram that will create an accurate three-dimensional model of theobject that can be viewed and measured from any angle.

Other advantages and objects of the invention will be apparent to thoseskilled in the art from the description of the invention which followswith reference to the following drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a typical lens aperture;

FIG. 1 a is a schematic side view illustration of a typical condenserlens;

FIG. 2 is a mask of the present invention at the aperture;

FIG. 2 a is the lens of FIG. 1 a with the mask of FIG. 2 disposed at theaperture;

FIG. 3 is another mask of the present invention at the lens aperture;

FIG. 3 a is the lens of FIG. 1 a with the mask of FIG. 3 disposed at theaperture;

FIG. 4 is another mask of the present invention at the lens aperture;

FIG. 4 a is the lens of FIG. 1 a with the mask of FIG. 4 disposed at theaperture;

FIG. 5 illustrates the mask of FIG. 4 at different phases of itsrotation;

FIG. 5 a is an embodiment of a mask of the present invention formed froman LED matrix;

FIG. 6 is a side view of a typical prior art microscope;

FIG. 7 is an embodiment of the present invention utilizing an off-axisiris diaphragm;

FIG. 8 is a side view of a lens having a gear-driven dynamic aperturemask of the present invention at its objective aperture;

FIG. 8 a is a plan view of the mask of the present invention shown inFIG. 8;

FIG. 9 is a side view of an embodiment of the present invention using aturret carrying multiple masks of the present invention;

FIG. 9 a is a plan view of the turret and masks of FIG. 9;

FIG. 9 b is the same as FIG. 9 a, except that the masks have a differentshape;

FIG. 10 is an embodiment of the present invention employing a slider onwhich multiple masks of the present invention are carried;

FIG. 11 is a side schematic view of an embodiment of the presentinvention incorporated in a phototube eyepiece for use with a camera;

FIG. 12 is a side schematic view of the present invention embodied in alight source;

FIG. 12 a is a plan view of the dynamic aperture mask of the presentinvention of FIG. 12;

FIG. 13 a is an illustration of the dynamic aperture mask of the presentinvention relative to a low NA objective;

FIG. 13 b is an illustration of the dynamic aperture mask of the presentinvention relative to a medium NA objective;

FIG. 13 c is an illustration of the dynamic aperture mask of the presentinvention relative to a high NA objective;

FIG. 14 a is an embodiment of a dynamic mask of the present inventionutilizing overlapping semi-circle opaque members;

FIG. 14 b is a view of FIG. 14 a with the members rotated to a differentrelative position;

FIG. 15 is an illustration of the dynamic aperture mask of the presentinvention in which the change in position of the light passing throughthe aperture is linear;

FIG. 15 a is a diagrammatic illustration of an image of an objectillustrated as shown in FIG. 15;

FIG. 16 is a side schematic illustration of an embodiment of the presentinvention utilizing a motor-driven optical fiber light source;

FIG. 17 is another side view schematic of another embodiment of thepresent invention utilizing a fiber optic light source;

FIG. 18 is another side view schematic of the present inventionutilizing a fiber optic light source;

FIG. 19 is a schematic side view of an object viewed with the presentinvention illustrating the movement of the elements of the object asperceived through a microscope utilizing the present invention;

FIG. 20 is a schematic illustration of the present invention embodied inan endoscope;

FIG. 21 is an illustration of the present invention utilizingoverlapping sector-shaped blades;

FIG. 21 a shows the blades of FIG. 21 extended to obscure a greaterportion of the aperture at which it is placed;

FIG. 22 is a schematic illustration of an embodiment of the inventionutilizing expanding bellows;

FIG. 23 a is an illustration of the present invention utilizingsector-shaped LCDs;

FIG. 23 b is FIG. 23 a with certain of the LCDs rendered opaque;

FIG. 23 c is yet another illustration of FIG. 23 a with other LCDsrendered opaque;

FIG. 24 is an illustration of the present invention utilizing an arrayof LEDs.

DETAILED DESCRIPTION OF THE INVENTION

The invention resides in methods and apparatus for continually changingthe portion of an objective aperture in an imaging optical system thatpasses light so that the object is continually being viewed from achanging angle, permitting the elements of the image of the object inthe foreground to be distinguishable from the elements of the image ofthe object in the background. Several structural embodiments of theinvention achieve this result.

Referring to FIGS. 1 and 1 a, a typical microscope condenser lens 11 hasan aperture 12 defining an area 13. A light beam 14 entering thecondenser 11 passes through the aperture 12 and emerges along theoptical axis 16. There being no occlusion of the aperture 12, its entirearea 13 is typically filled with the light beam 14.

Referring to FIGS. 2 and 2 a, a mask 17 having an opaque sector 18 and asector-shaped mask aperture 18 a which can pass light is disposed at thelens aperture 12. A light beam 15 entering the lens 11 passes throughthe mask aperture 18 a (which is the three-quarters of the lens aperture12 not occluded by the sector 18) and emerges from the lens at an angleØ to the optical axis 16. The beam 15 emerges from lens 11 as an obliquebeam (relative to the optical axis 16) and the angle Ø is a measure ofthe obliquity of the beam.

Referring to FIGS. 3 and 3 a, a mask 19 having an opaque sector 22 and asemi-circular mask aperture 22 a which can pass light is disposed at thelens aperture 12 occluding one-half of the area of the aperture 12. Alight beam 21 entering lens 11 passes through the half of lens aperture12 aligned with mask aperture 22 a and emerges from the lens 11 at anoblique angle Ø.

Referring to FIGS. 4 and 4 a, a mask 23 having an opaque sector 26 and asector-shaped mask aperture 26 a is disposed at lens aperture 12,three-quarters of which it occludes. A light beam 24 entering lens 11passes through only the mask aperture 26 a and emerges from the lens 11at an angle Ø to the optical axis 16. As the opaque area of the maskincreases (the mask aperture area decreases), the beam angle Øincreases. Stated somewhat differently, as the area of the mask aperturedecreases, so does the cone angle of the beam that emerges from the lensas measured at the focal plane 28 of the lens.

For each of the embodiments of FIGS. 2 a-4 a, an object 27 at an image(focal) plane 28 is illuminated with oblique illumination, and thus,ultimately viewed from an angle relative to the optical axis 16.

When it is stated that a mask or other element is located “at” anobjective aperture, it shall mean, and will be understood by thoseskilled in the art, that the mask or other element is at that proximityto the objective aperture that an image of the mask or other elementdoes not appear at an image plane in the optical system.

By rotating any of masks 17, 19 or 23, the portion of the lens aperture12 which passes light is continually changed. As the mask rotates, beam24, for example (FIG. 4 a), will rotate about optical axis 16 so thatthe view of the image of object 27 will be from a continually changingangle, allowing the observer to interrogate the object through 360degrees. By way of contrast, stereo 3-D viewing only allows the observerto view the object from two angles—a left angle and a right angle.

As used herein, the term “dynamic aperture mask” means a mask having anaperture located at an objective aperture which continuously allowslight to pass, but limits the area of the objective aperture throughwhich light passes to only an off axis portion of the objectiveaperture, and means that continuously rotates the mask through multiplerotations, which causes the portion of the objective aperture thatpasses light to continuously change and thereby continuously change theangle of illumination and thereby create motion parallax.

Referring also to FIG. 5, the rotation of mask 23 about optical axis 16constantly moves the mask aperture 26 relative to the objective aperture12 and continuously changes the portion of objective aperture 12 thatpasses light.

When a dynamic aperture mask, such as mask 23, is located at anobjective aperture in an optical system illumination path, the objectwill be illuminated with oblique illumination and viewed from acontinually changing angle as the mask rotates. When the object isilluminated with oblique illumination in this way, the image of theobject will be enhanced in a manner taught by Greenberg U.S. Pat. No.5,345,333.

When a dynamic aperture mask, such as mask 23, is disposed at anobjective aperture in the optical system image path (i.e., after theobject has been illuminated), the image of the object will also beviewed from a continually changing angle, and thus seen in 3-D, but willnot have the enhanced effects of oblique illumination.

While the embodiment of the invention described above teaches the use ofa dynamic aperture in the shape of a sector of a circle with the vertexof the sector at the optical axis, the invention is not so limited. Theinvention resides in continually changing the portion of the objectiveaperture through which light passes so that the angle from which theobject is viewed is continually changed. This is also accomplished bycontinuously moving a shaped beam through different portions of theaperture. An LED array at the aperture plane that is controlled (turnedon or off) in a way that simulates a light source continuously movingthrough a different portion of the objective aperture also serves thepurpose of the invention to achieve its objects.

Referring to FIG. 5 a, an array 30 of light-emitting diodes (LEDs) 32 islocated at an objective aperture 29. The diodes 32 are controlled bycontrol (switching) system 31 to create light patterns and sequencesthat continuously change the portion of the objective aperture(condenser aperture) through which light is emitted. The array 30 can becontrolled to produce a sector-shaped light pattern that rotates aboutthe optical axis of the aperture 29 or any other beam that can be movedcontinuously to create motion parallax.

Referring to FIG. 6, a typical optical system using Köhler illuminationfor imaging an object is a microscope 41 having an objective lens 42with an objective lens aperture 43, and a condenser lens 44 having anaperture 46 which is conjugate to the objective lens aperture 43, andaccording to the definition used here, an objective aperture. Otherobjective apertures occur in the microscope at light sources 47 and 48,as well as at the eye-point 49 of phototube 50 and the eye-point 51 ofeyepiece 55. Another objective aperture 52 is located in the opticalsystem through relay lenses (not shown). As referred to herein, an“eye-point” is the location where a viewer's eye would be located toview the image of the object 53. Because an observer's eye has afocusing lens, the image is not in focus at the eye-point. The eye-pointis one of the apertures conjugate to the objective aperture where theimage is not in focus.

Placing a dynamic aperture mask, such as mask 23 (FIG. 4), at any of theobjective apertures 43, 46, 47, 48, 49, 51 or 52 of the microscope 41will create a viewable moving 3-D image of an object 53 in the otherwise2-D microscope 41.

Microscope 41 operates as a transmitted light microscope when the object53 is illuminated by light source 54. By placing dynamic aperture 23 atobject plane 46 or 48 (in the illumination path), the object 53 isilluminated with oblique illumination that continually changes itsangle, whereby the angle from which the image of the object 53 is viewedat eyepiece 55 is continually changing, giving the image the appearanceof moving in three-dimensional space. Placing a dynamic aperture, suchas mask 23 (FIG. 4), at any objective aperture 43, 49 or 51 (in theviewing path) of microscope 41 will cause the image of the object 53 tobe perceived as moving through three-dimensional space and, thus,appearing as 3-D, even though not illuminated by oblique illumination.

It will be readily apparent to those skilled in the art that bysubstituting a standard condenser with a condenser 44 having a dynamicaperture mask, such as that shown in FIG. 4, at objective aperture 46, amicroscope capable of only generating and viewing a two-dimensionalimage can be economically converted to a microscope that can create andview an image in real-time 3-D without filters or special glasses. Theinsertion of such a dynamic aperture at objective aperture 52, or any ofthe other microscope objective apertures, will likewise convert amicroscope limited to 2-D into a microscope capable of viewing an objectin 3-D (even if the microscope has only a monocular viewing system).

The benefits of the present invention can be realized utilizing variousconfigurations of parts creating dynamic mask apertures of variousgeometric shapes and sizes. The particular physical embodiment or sizeand shape selected for a mask and its dynamic aperture will depend on anumber of factors, including the effect that is desired and thecharacteristics of the object under examination. Thus, while particularshapes for a dynamic mask aperture may be more advantageous than othersin certain circumstances, all shapes and sizes of dynamic apertures andall physical embodiments that create motion parallax and a 3-D image arewithin the teachings of the invention. Similarly, which of the severalobjective apertures in an optical imaging system where a mask (dynamicaperture) of the present invention is located is a matter of choicedependant on the circumstances of the investigation.

For example, placing the dynamic aperture at the condenser lens apertureis good for transmitting light applications, while placing it in theillumination system is good for both transmitted and reflected lightapplications. Placement at the illumination system has the addedadvantage of allowing for special optical systems, such as phasecontrast optics. Additionally, placing the dynamic aperture at the photoeyepiece makes it compatible with florescence microscope.

Referring to FIG. 7, in one embodiment of the invention, a standard irisdiaphragm 58 having an opening 59 which is variable in size, asindicated by dashed lined 61, is held within a circular frame 62 bysprings 63 and 64 and positioning screws 66 and 67. The location of theiris opening 59 within the frame 62 is controlled by screws 66 and 67.When the frame-held iris 58 is positioned to locate the opening 59 offthe center of an objective aperture 68, rotation of the frame 62,together with the diaphragm iris 58, causes the opening 59 to rotatewithin the aperture 68 and continuously change the portion of theaperture 68 that passes light. Frame 62 can be rotated by any one ofseveral well known drive systems, including friction, belt, or geardrive.

Referring to FIGS. 8 and 8 a, a lens 71 has a dynamic aperture mask 72with a sector-shaped aperture 73 located at the lens objective aperture70. Gear teeth 74 on the periphery of the dynamic aperture mask 72 meshwith a gear 76, which is rotated by a shaft 77, which is connected to amotor 78 or other means for rotating the shaft. As the gear 76 drivesthe dynamic aperture mask 74, the mask aperture 73 continuously changesthe portion of the objective aperture 70 that passes light, thusproducing the motion parallax which produces a 3-D effect.

Referring to FIGS. 9 and 9 a, instead of locating a single dynamicaperture mask, such as mask 72 (FIG. 8), at the objective aperture of alens, in this embodiment of the invention, a rotating turret 81 isdisposed in the plane of the objective aperture 80 of a lens 82. Theturret 81 carries four different dynamic aperture masks 83, 84, 86 and87, each having an aperture 83 a, 84 a, 86 a and 87 a, respectively, ofa different geometric shape. The particular shapes illustrated are onlyby way of example of the possible shapes for mask apertures that arewithin the scope of the invention. A standard iris diaphragm 88 can alsobe provided on the turret 81 for standard operation of the lens.

A drive gear 89, driven by a gear motor and shaft 91, engages theperimeter 92 of turret 81, enabling the turret 81 to be rotated aboutits axis 93. The drive gear 89 can thus position the turret 81 to alignany of the masks 83, 84, 86, 87 or iris 88 with the aperture 80 of lens82, as desired. Positioning turret 81 by hand is, of course, also anoption. The alignment of a dynamic aperture mask with the objectiveaperture 80 of lens 82 also aligns the aperture mask with an aperturemask drive gear 94 for rotating the aligned mask. This embodimentpermits the easy selection of one of a variety of different dynamicaperture masks for use as the need arises. The shape of each dynamicaperture can be designed for specific applications, such as phasecontrast microscopy. Referring to FIG. 9 b, a mask 95 on turret carrier81 has an aperture 95 a in the shape of a portion of a phase annulus. Byrotating the phase annulus aperture 95 a, 3-D phase contrast effects areachieved. The other masks illustrated provide apertures for use withdifferent NA lenses and different shaped annuli.

Referring to FIG. 10, in another embodiment of the invention, a slidecarrier 96 carries three rotatable dynamic aperture masks 97, 98 and 99,each having an aperture 97 a, 98 a and 99 a, respectively, of adifferent geometric shape and each rotated by a belt 101 driven by agear 102. Once again, the particular shapes illustrated are only asample of the many different shapes that could be used. When the slide96 is moved relative to a lens aperture (such as objective aperture 80of FIG. 9), one of the dynamic aperture masks 97, 98 or 99 can bebrought into alignment with the objective aperture and the optical axisof the optical system. Rotation of the mask will continuously change theportion of the objective aperture through which light passes, and thusproduce the motion parallax which produces the 3-D effect of the presentinvention. A conventional iris diaphragm 103 can be conveniently locatedon the carrier 96, as well, for conventional use of the optical imagingsystem with which the carrier 96 is used.

Referring to FIG. 11, the present invention is embodied in an adapterfor a microscope phototube. An adapter 106 contains a photo eyepiece 107exclusively used to focus a light beam at an eye-point 108, which iscoincident with an objective aperture 109. Light beam 105 carries animage of an object (not shown) that is “seen” at an image plane 111 in acamera 112 that is supported on the adapter 106 by a camera connector113. Camera 112 can be a digital camera, a video camera or any otherdevice capable of recording images.

A dynamic aperture mask 114 is located at the objective aperture 109 androtated by a gear 116, supported on a shaft 117, driven by a motor 118.Dynamic aperture mask 114 can include an aperture of any desired shape,such as those illustrated in FIGS. 9 a and 10, so long as when theaperture mask 114 is rotated by gear 116, the portion of the aperture109 that passes light is continually changed whereby the image “seen” atimage plane 111 of camera 112 is from a continuously changing angle.

By replacing a standard phototube with the phototube 106 of the presentinvention, a microscope capable of only creating and capturing a 2-Dimage can be easily converted into a microscope that can capture a 3-Dimage. One of the advantages of this embodiment of the invention is thatit is compatible with all forms of microscopy, such as phase contrast,differential interference contrast, florescence, transmitted orreflected light microscopy.

Another embodiment of the present invention that conveniently andeconomically converts a 2-D microscope into a 3-D microscope is seen inFIGS. 12 and 12 a. A lamp housing 121 having a dovetail mountingconnector 122 that permits it to attach to a standard microscope lamphousing contains a lamp light source 123 and a lamp condenser lens 124.The light source 123 directs a light beam 125 onto a diffusing filter126 from which the light beam is directed onto lamp condenser lens 124,and from there, into the optical path of a microscope (not shown).

The lamp condenser lens 124 creates an objective aperture 127, at whichis located a dynamic aperture mask 128 having a sector-shaped aperture129 which sweeps through the objective aperture 127 when driven by agear 131 mounted on a shaft 132 rotated by a motor 133. Once again, asthe mask aperture 129 rotates, the portion of the objective aperture 127that passes light beam 125 is continually changed so that an objectilluminated by the light beam 125 in a microscope optical system will becontinuously illuminated from a changing angle and thus be perceived in3-D by virtue of the motion parallax created by light beam 125. Anadvantage of this embodiment of the invention is that it works withphase contrast optics by continuously illuminating a different portionof a standard phase contrast annulus, regardless of the size of thephase annuli.

Referring to FIGS. 13 a, 13 b and 13 c, one of the advantages of theembodiment of the present invention that utilizes a sector-shapedaperture 136 in an aperture mask 137 is that it operates equally with anobjective of low numerical aperture (NA), as well as an objective with ahigh NA.

Thus, while the mask 137 is substantially larger than the low NAobjective 138, rotation of the mask 137 nonetheless continuously changesthe portion of objective 138 through which light can pass. Although themask 137 stays the same in size, its ability to produce effective motionparallax by rotating at the mask aperture 136 of a medium NA objective139 (FIG. 13 b) or a high NA objective 141 (FIG. 13 c) remains the same.Thus, in terms of what an objective aperture “sees,” mask 137 isproperly sized for a wide range of NA lenses. One shape fits manydifferent size objective lenses with equal effect.

Referring to FIGS. 14 a and 14 b, another embodiment of the inventionprovides a rotatable dynamic aperture mask where the aperture is asector of a circle which is variable in size. A dynamic aperture mask144 includes a support ring 146 containing two semi-circular opaqueaperture-forming members 147 and 148 which are rotatable within ring 146about a center point 149. By overlapping a portion of the members 147and 148, an aperture 151 is created which can pass light. Gears 152 onthe outer circumference of the ring 146 mesh with a drive gear 153 forrotating the entire dynamic aperture mask 144. The size of aperture 151is varied by rotation of the opaque members 147 and 148 relative to oneanother until the size of the aperture 151 best suits the needs of theinvestigation being conducted. As the aperture 151 increases in size,the illumination or viewing affected by the dynamic aperture decreasesin apparent movement and vice versa. As the aperture 151 is decreased insize, the contrast and depth of field is increased.

A number of other mechanical and electro-mechanical devices are capableof creating a variable-size aperture in a dynamic mask, such as mask144. Details of such other mask configurations are set forth in mycopending application Ser. No. 09/715,636, for Method and Apparatus forCreating Real-Time 3-D Images and Constructing 3-D Models of an ObjectImaged in an Optical System, filed Nov. 17, 2000. In particular, insteadof overlapping opaque semi-circular members 147 and 148, the spacewithin ring 146 could contain overlapping blade structures, such asshown in FIGS. 21 and 21 a, which can be adjusted to create avariable-size aperture 151. Referring to FIG. 22, a bellow-typeexpandable opaque mask 150 can also create a variable-size aperture 151.Similarly, liquid crystal diodes (LCDs), such as shown in FIGS. 23 a, 23b and 23 c, can be used to create a variable light-passing aperture 151within ring 146. FIG. 23 a illustrates a circle formed by eight equalsector-shaped LCDs 154, all conditioned to pass light. In FIG. 23B, twoadjacent LCDs 154 have been conditioned to be opaque to light so thatthe remaining LCDs form a sector-shaped aperture that passes light. FIG.23C illustrates the LCDs 154 conditioned such that only two adjacentsectors pass light to create an aperture 151 different in shape thanthat of FIG. 23 b. The particular variable-shaped rotatable aperturemask 144 illustrated in FIGS. 23A, 23 b and 23 c is but an example ofthe shaped that can be formed using LCDs. The advantage to using LCDs isthat any shape can be achieved and quickly changed to any other shape,including shapes that would be difficult, if not impossible, to achievewith physical masks. In addition, the shapes and their transitions canbe computer-created and controlled to create dynamic apertures tailoredto specific needs. In addition to sector-shaped LCDs, a mask can beformed from an X-Y array of LCDs that can be switched to create anyshape desired that can be moved continuously so that light can be causedto continuously move through a different portion of an objectiveaperture. See Kley U.S. Pat. No. 4,561,731.

Thus, in addition to the plurality of different-size apertures in adynamic aperture mask, such as illustrated in FIGS. 9 a and 10, theinvention can also be embodied in a single mask having a variable-sizeaperture.

All of the embodiments of the invention disclosed so far include arotating mask aperture at an objective aperture to continually changethe portion of the objective aperture which passes light in order tocreate motion parallax and a 3-D view. The objects of the invention areachieved, however, by different forms of a dynamic aperture, as well asby a shaped beam in place of an aperture mask.

Referring to FIGS. 15 and 15 a by moving a shaped light beam or anoccluding mask back and forth across an objective aperture 156, theportion of the aperture which passes light is continually changed, asbest seen by the progressive change in the portion of aperture 156 whichpasses light. As the light beam or occluding mask swings across theaperture 156 to one extreme of its travel light is passes throughportion 156 a of aperture 156. As it retreats from that extreme lightpasses through portion 156 b until the entire aperture is filled withlight when the beam is centered. As the beam is moved beyond center theportion 156 d passes light and when the beam reached the extremeposition in the other direct portion 156 e passes light. As the beamswings back, the pattern is reversed. By occluding the aperture in thisway, or by passing a shaped light beam over the aperture 156, eachelement 157 of an object being viewed (not shown) appears to rock backand forth, as indicated by motion arrows 158. The combined effect of therocking motion of the elements of an object through the methods andapparatus of the present invention reveals the three-dimensionalstructure of the object similar to the three-dimensional view created bythe rotating dynamic aperture mask described above.

One of the advantages in using a rotating sector of a circle or othergeometric shape rotating about the center of the objective aperture tocontinually change the portion of the aperture which passes light isthat the intensity of the light passed by the aperture remains constant,whereas in the embodiment of FIGS. 15 and 15 a, the light intensityvaries considerably. This darkening and lightening effect can beovercome or ameliorated by a feedback system that continually changesthe intensity of the light source to effect an evenly illuminated image.

Referring to FIG. 16, one way to achieve the variable occlusion of theobjective aperture shown in FIG. 15 is by causing a fiber optic bundle161 illuminated by a light source 160 to reciprocate relative to a lens162 and its objective aperture 163. A reciprocating motor 164 andconnecting link 166 cause the fiber optic bundle 161 to move back andforth a distance sufficient to move a light beam 167 from the fiberoptic bundle 161 across the lens 162 so that, except when the fiberoptic bundle is centered, some portion of the objective aperture 163 isnot illuminated by the light beam 167, as illustrated in FIG. 15. Thenumbers 156 a, 156 c and 156 e indicate the positions of bundle 161 thatcreate the aperture portions that pass light of the same numericaldesignations in FIG. 15.

Referring to FIG. 17, a fiber optic bundle 169 receiving light from alight source 171 produces a beam 172 having a cross-sectionsubstantially smaller than the objective aperture 173 of a lens 174 ontowhich the beam is directed. A motor 176 connected to the fiber opticbundle 169 by a link 177 causes the fiber optic bundle to move in acircle, as indicated by motion arrow 178. As beam 172 rotates, theportion of aperture 173 that contains light continually changes,producing substantially the same effect as described in connection withthe dynamic aperture mask embodiment of the invention. (See particularlyFIG. 7.) As with a dynamic mask, motion parallax is created, giving riseto a 3-D effect. In the shaped light beam embodiment of the invention,the intensity of the light that passes through the aperture 173 isessentially constant.

Referring to FIG. 18, a light source 181 directs a beam of light 182onto a mirror 183, which reflects the light beam onto a lens 184 throughthe objective aperture 186. A motor 187 connected to mirror 183 througha link 188 causes mirror 183 to move in such a way as to sweep beam 182across the aperture 186 so as to create the variable occlusionillustrated in FIG. 15.

Another way of creating a shaped light beam is to use an array of lightemitting diodes (LEDs) at an objective aperture. Referring to FIG. 24,an array 179 of LEDs 180 can be controlled to emit light in any patterndesired. Moreover, the selected shape can be caused to move so that whenplaced at an objective aperture, light will pass through a differentportion of the aperture on a continuous basis. The dark shaded diodes179 form a sector 179 a and represent diodes that are emitting light.That sector can be caused to rotate, creating the same result as thedynamic aperture mask of FIG. 4, for example.

One application of the present invention is to create a series ofdiscrete obliquely angled images of an object at selected planesthroughout the object. The series of images so created can be digitizedand analyzed by a computer program to create a very accuratethree-dimensional model of the object that can be viewed and measuredfrom any angle. Thus, the present invention can be combined with anordinary microscope to create the hardware portion of a tomographicmicroscope.

Referring to FIG. 19, an object 191 consists of a plurality ofobject-forming elements 191 a, 191 b, 191 c, 191 d, 191 e, 191 f, 191 gand 191 x. The ran object 191 is being imaged by an optical imagingsystem, such as a microscope, having an optical axis parallel to axes193 and a focal plane at 194 within the object 191. When the object 191is viewed in an optical viewing system that includes an objectiveaperture through which a light beam continuously passes through adifferent portion, as taught by the present invention, the variouselements of object 191, other than those which are at the image plane194, precess about optical axis 193 in circles that increase in diameteras the distance of the element from the image plane 194 increases. Thus,for example, element 191 a will move in a larger circle about axis 193than element 191 b, which is closer to the image plane 194. Element 191c, which is at the image plane, will not move at all, whereas element191 d, which is about the same distance from the image plane 194 aselement 191 b, will circle the optical axis 193 in a circle of about thesame diameter as the circle traveled by element 191 b, but be in anopposite phase thereto. Each element of the object 191 that is off theoptical axis 194, such as elements 191 f and 191×, will precess about anaxis 193. The combined effect of the apparent movement of the variouselements of the object 191, as seen in an optical system employing thepresent invention, is that the entire object 191 appears to move inthree-dimensional space so as to make it possible to discern thoseelements of the object which are in the foreground from those which arein the background and thus appear in 3-D.

Because all of the elements of the object 191 that are off of the imageplane 194 move with time, it is possible, using known digitizing andcomputer programming techniques, to eliminate from an image of object191 all of the elements, other than those that appear at the imageplane, by eliminating all elements that change location with time. Inthis way, it becomes possible to create an image of the object at aselected plane in the object, such as plane 194. By moving the imageplane to various locations within object 191 (by, for example,refocusing the microscope), it becomes possible to create a series offocal plane specific images of object 191, and from that series ofimages, create an accurate model of the object 191 that can be viewedand measured from any angle.

Referring to FIG. 20, the dynamic aperture system of the presentinvention can be used advantageously with imaging techniques, such asendoscopy.

As is typical in endoscopy, a slender fiber optic tube 201 is insertedinto a body 202 for the purpose of viewing interior portions of the body202 through a lens 203 in the distal end of the fiber optic tube 201.The images created by the lens 203 are directed to a camera 204 wherethey are recorded or displayed in real-time by a monitor 206. One of thedifficulties in dealing with endoscopic images is that they lackthree-dimensional perspective making it difficult to determine thespacial relationship of the various images being viewed.

The present invention provides a means for giving three-dimensionalperspective to the endoscopic images. A lens 207 between the camera 204and the endoscopic tube 201 creates an objective aperture 208 outside ofthe body 202 where it is convenient to locate a dynamic aperture mask209 of the present invention which can be driven by a motor 211, aspreviously described.

It will be obvious to those skilled in the art that the dynamic aperture209 can be any of the various embodiments of the invention describedtherein, as well as those which are equivalent thereto, and will notdepart from the invention. In an endoscope, as in any imaging systemthat has or is capable of having an objective aperture, the presentinvention provides a means for creating motion parallax from otherwisetwo-dimensional images so as to create a three-dimensional perspective.

Obviously, many modifications and variations of the present inventionare possible in light of the above teachings. It will, therefore, beunderstood by those skilled in the art that within the scope of theappended claims, the invention may be practiced otherwise than asspecifically described.

1. In an optical system for viewing an object illuminated by a lightbeam and having an objective aperture through which the light beampasses, the improvement comprising: rotatable means permitting thecontinuous passage of light through the objective aperture, but limitingthe light beam to passing through only a portion of the objectiveaperture; and means for continuously rotating said rotatable means aplurality of revolutions to continuously change the portion of theobjective aperture through which light passes while the object is beingviewed.
 2. The improvement of claim 1 wherein the optical system isfurther described as having a viewing path and the objective aperture isin the viewing path.
 3. The improvement of claim 2 wherein the viewingpath is further described as including an eye point and the objectiveaperture is between the eye point and the object.
 4. The improvement ofclaim 2 wherein the viewing path is further described as including aneye point and the objective aperture is at the eye point.
 5. Theimprovement of claim 1 wherein the optical system is further describedas having an illumination path and the objective aperture is in theillumination path.
 6. The improvement of claim 5 wherein theillumination path is further described as including a light source andthe objective aperture is between the light source and the object.
 7. Inan optical system for viewing an object and having an objective aperturewith an axis through which light passes, the improvement comprising: adynamic aperture mask disposed at the objective aperture; a dynamicaperture mask having an aperture located at the objective aperture whichcontinuously allows light to pass, but limits the area of the objectiveaperture through which light passes to only an off axis portion of theobjective aperture; and means for continuously rotating the mask throughmultiple rotations, which causes the portion of the objective aperturethat passes light to continuously rotate about the objective apertureaxis and thereby continuously change the angle of illumination andthereby create motion parallax.
 8. The improvement of claim 7 whereinsaid dynamic aperture mask is an array of LCDs.
 9. The improvement ofclaim 7 wherein said dynamic aperture mask is an opaque disk with asector-shaped aperture.
 10. The improvement of claim 7 wherein saiddynamic aperture mask is overlapping leaflets.
 11. The improvement ofclaim 7 wherein said dynamic aperture mask is two overlappingsemi-circular opaque discs.
 12. The improvement of claim 7 wherein saiddynamic aperture mask is a plurality of sector-shaped LCDs.
 13. Theimprovement of claim 7 wherein said dynamic aperture mask has a variablesize aperture.
 14. The improvement of claim 13 wherein said variablesize aperture is an iris diaphragm disposed off the objective apertureaxis.
 15. The improvement of claim 7 wherein the aperture in saiddynamic aperture mask has the shape of a sector of a phase annulus. 16.In an optical system for viewing an object and having an objectiveaperture through which light passes, the improvement comprising: acarrier disposed at the objective aperture and moveable relativethereto; a plurality of dynamic aperture masks on said carrier each ofwhich can be aligned with the objective aperture by moving said carrierrelative thereto wherein each said dynamic aperture mask comprises: anaperture located at the objective aperture which continuously allowslight to pass, but limits the area of the objective aperture throughwhich light passes to only an off axis portion of the objectiveaperture; and means that continuously rotates the mask through multiplerotations, which causes the portion of the objective aperture thatpasses light to continuously change and thereby continuously change theangle of illumination and thereby create motion parallax.
 17. Theimprovement of claim 16 wherein the apertures of said dynamic aperturemasks are sectors of circles of different sizes.
 18. The improvement ofclaim 16 wherein the apertures of said dynamic aperture masks aresectors of phase annuli of different sizes.
 19. In a method for creatinga 3-D view of an object in an imaging system having an objectiveaperture with an axis through which a light beam passes, the stepscomprising: causing the light beam to pass through only a portion of theobjective aperture; and continuously moving the light beam about theobjective aperture axis within the objective aperture to create motionparallax whereby the object is viewed in 3-D.
 20. The method of claim 19wherein a dynamic aperture mask is used to cause the light to passthrough only a portion of the objective aperture and rotate about theobjective aperture axis wherein said dynamic aperture mask comprises anaperture located at the objective aperture which continuously allowslight to pass, but limits the area of the objective aperture throughwhich light passes to only an off axis portion of the objectiveaperture; and means for continuously rotating the mask through multiplerotations, which causes the portion of the objective aperture thatpasses light to continuously change and thereby continuously change theangle of illumination and thereby create motion parallax.
 21. The methodof claim 19 wherein an array of LCDs is used to cause the light to passthrough only a portion of the objective aperture.
 22. The method ofclaim 19 wherein an array of LEDs is used to cause the light to passthrough only a portion of the objective aperture.
 23. The method ofclaim 19 wherein a shaped beam is used to cause the light to passthrough only a portion of the objective aperture.
 24. The method ofclaim 19 wherein the imaging system is a light microscope having anillumination path including the objective aperture and a viewing pathhaving at least one additional objective aperture wherein the objectiveaperture through which light passes through only a portion is in theillumination path.
 25. The method of claim 19 wherein the imaging systemis a light microscope having an illumination path including theobjective aperture and a viewing path having at least one additionalobjective aperture wherein the objective aperture through which lightpasses through only a portion is in the viewing path.
 26. The method ofclaim 19 wherein the imaging system is a light microscope having a lightsource wherein the objective aperture through which light passes throughonly a portion is in the light source.
 27. The method of claim 26wherein the microscope is a phase contrast microscope.
 28. The method ofclaim 19 wherein the imaging system is a light microscope having a phototube and the objective aperture through which light passes through onlya portion is at the photo tube.
 29. The method of claim 19 wherein theimaging system is a light microscope having an eye piece and theobjective aperture through which light passes through only a portion isat the eye piece.
 30. The method of claim 19 wherein the microscope is aphase contrast microscope.
 31. In a phase contrast microscope having alight source with an objective aperture that has an axis and throughwhich light is directed the improvement comprising: dynamic aperturemeans permitting the continuous passage of light through the objectiveaperture, but limiting the light to passing through only an off axisportion of the objective aperture and; means continuously rotating saiddynamic aperture about the objective aperture axis multiple revolutionsto create motion parallax.
 32. In the phase contrast microscope of claim31 where the dynamic aperture means is an aperture mask.
 33. In a methodof creating a three dimensional model of a three dimensional objecthaving a plurality of elements using a light microscope having anobjective aperture through which a light beam passes and a focal planethe steps comprising: locating the microscope focal plane at variouslocations within the object; for each location of the focal plane withinthe object: cause the light beam that passes through the objectiveaperture to pass through only a portion of the objective aperture;continuously change the portion of the objective aperture through whichthe light beam passes.
 34. In a method of creating a three dimensionalmodel of a three dimensional object having a plurality of elements usinga light microscope having an objective aperture through which a lightbeam passes and a focal plane the steps comprising: locating themicroscope focal plane at various locations within the object; for eachlocation of the focal plane within the object: cause the light beam thatpasses through the objective aperture to pass through only a portion ofthe objective aperture; continuously change the portion of the objectiveaperture through which the light beam passes; digitize the image of theobject at each location; eliminate from the digitized image all elementsof the object that change location while the portion of the objectiveaperture through which the light beam passes is continuously changedthereby obtaining a focal plane specific image; combine the focal planespecific images for each location of the focal plane within the object.35. In an endoscopic device having an optical path for light thatincludes a probe and lens with an objective aperture for entering into abody to transmit a view of the interior thereof to a viewing systemoutside the body, the improvement comprising: an objective apertureoutside the body in the optical path between the lens and the viewingsystem; and means continuously changing the portion of said objectiveaperture outside the body that passes light.
 36. The improvement ofclaim 35 wherein said means is a dynamic aperture mask disposed at saidobjective aperture.
 37. The improvement of claim 36 wherein said dynamicaperture mask is an array of LCDs.
 38. The improvement of claim 36wherein said dynamic aperture mask is an expandable bellows.
 39. Theimprovement of claim 36 wherein said dynamic aperture mask isoverlapping leaflets.
 40. The improvement of claim 36 wherein saiddynamic aperture mask is two overlapping semi-circular opaque discs. 41.The improvement of claim 36 wherein said dynamic aperture mask is aplurality of sector-shaped LCDs.
 42. The improvement of claim 36 whereinsaid dynamic aperture mask has a variable size aperture.
 43. Theimprovement of claim 42 wherein said variable size aperture is sectorshaped.